Addressing U.S. troops returned from Iraq, Vice President Joe Biden has pointed to successes of the more than seven year American military involvement there. The remarks came amid concern in Iraq over recent bomb attacks, despite a general decline in violence, underscoring the challenges facing Iraqi forces as the U.S. draws down its forces.

The vice president's remarks came in a speech at Fort Drum, New York, as he joined in a welcome home event for U.S. Army troops of the 2nd Brigade Combat Team from Iraq.

U.S. troops, he said, enabled Iraq's leaders and security forces to persevere and establish a political process, while those who sought to make chaos and destruction the hallmark of a new Iraq failed.

While the final chapters in Iraq remain unwritten, with al-Qaida and other violent extremists continuing efforts to disrupt progress, the vice president looked ahead to the day America's combat mission will end.

"One month from now, as President Obama pledged, America's combat mission in Iraq will end," said Vice President Biden. "By August 31, more than 145,000 troops on the ground when this Administration took office, will be 50,000 troops on the ground, a total of 95,000 troops home."

Biden said American troops paid a high price in enabling the dawn of a new era in which Iraqis have an opportunity to live a better life, and in which in his words Iraqi political leaders can match the courage of their citizens with their own courage and commitment.

The United States he noted will be transitioning to a civilian-led effort in Iraq focusing on advising and assisting Iraqi forces, counter-terrorism, and protecting U.S. civilian and military personnel.

Though he spoke during a week in which there has been a spate of bomb attacks in Iraq, the vice president said an Iraq once mired in sectarian conflict has been replaced by one in which politics has "broken out" and where people have rejected the tactics of al-Qaida and extremism.

"While challenges remain, the Iraqi people have overwhelmingly rejected the ugly face of al-Qaida and other violence extremists who have sought to tear that country apart," said Mr. Biden. "Iraqis have had to take that step themselves, and they have, but you made it possible."

The remarks also came in the middle of a week in which media and public attention in the U.S. and around the world focused on the other long-running conflict President Obama inherited, the nine-year-old war in Afghanistan.

A letter the president received this week from two key Democratic senators was a reminder of intense concern in the U.S. Congress about Afghanistan, based on what U.S. lawmakers see as lessons learned from the conflict in Iraq.

Senators Jim Webb and Russ Feingold, both members of the Senate Foreign Relations Committee, referred to the security agreement the Bush administration negotiated with Iraq, one they note was not first submitted to the Senate for review.

Saying they do not believe a long-term, open-ended presence of U.S. troops in Afghanistan serves the national interest, the lawmakers urge the president not to repeat what they call a damaging precedent set in Iraq by failing to submit any security agreement with Afghanistan for Senate review.

The letter from Webb and Feingold comes in the wake of the public release by the WikiLeaks website of more than 90,000 pages of documents detailing U.S. military operations in Afghanistan, with information suggesting among other things that elements in Pakistan continue to provide aid to Afghan Taliban forces.

President Obama has ordered the beginning of a U.S. military drawdown in Afghanistan in July next year. The president and military commanders stress this will be based on conditions on the ground. A major review of Afghanistan takes place later this year.

In his address Wednesday to troops returned from Iraq, Vice President Biden also noted the strain of multiple deployments to Iraq, as well as Afghanistan. And he underscored the administration's commitment to care for wounded soldiers, and support families of service men and women killed in action.